John Deere Fuel Shutoff Solenoid Thermistor Fix

John Deere 4200, 4300, 4400 Tractor Fuel Shutoff Solenoid Thermistor Fix. This doesn't apply to the 4x10 series, since those use a electronic controller to control the Solenoid. Thanks to @LGEZ53S for correcting me on this.

[@LGEZ53S]

None of the J.D. 4X10 series tractors (or newer), including this 4210 use a thermistor in the fuel shutoff solenoid valve control circuit.

[@darrenmas]

Thanks for your response

[@MikeOrazzi]

I forgot I bought one of these and never installed it. Not sure where I put it, that was years ago, maybe some day if the part comes out of hiding.

[@darrenmas]

Thanks for your feedback. If your having starting issues related to not enough fuel and solenoid bench tests good then this is probably the next part to test/replace.

[@mikekosar6135]

I’ve seen SO many problems with these selinoid’s… this is the first I’ve seen this… diesel

[@darrenmas]

Thanks for your response. The thermistor is really tough to troubleshoot. It can work/fail intermittently. If it’s a JD 4x00 series with hard starts related to not enough fuel it could be a bad thermistor.

[@MikeOrazzi]

I'd like to know where the thick black oil comes from that seems to be clogging up my fuel shut off solenoid. I put a new one and and have the same issue. @@darrenmas

[@darrenmas]

@@MikeOrazzi is the oil inside the solenoid? The solenoid should be strong enough to pull in even with thick oil on the shaft/plunger. You should get 12 volts on the primary wire and about 5 volts on the secondary wire. Most solenoid problems I’ve seen on the 4x00s is with the primary not getting 12volts when starting.

[@MikeOrazzi]

Yes, I plunge it a few times and the oil comes out. So, it might be that the thermistor isn't letting enough volts through then. @@darrenmas